Your system may display the isPostback_RC_Pendingupdates error if system drivers, especially chipset drivers (such as Intel ME), are not updated. In addition, a corrupted Windows Update agent or a corrupted Windows installation can cause the mentioned error.

The problem occurs when the user tries to update the faulty system and the user runs Windows troubleshooter.

Please disconnect all external devices such as USB, external hard drive, etc. of the system before looking for solutions.

Run Windows Update Troubleshooter

Disable the measured connection for your network

Users with limited data plans usually change their network type to metered connection, which limits the operation of various applications and services (including Windows Update). In this case, disabling the measurement connection setting for your network may resolve the issue.

Run BITS Troubleshooter